Ecological effects of the Lawn Lake Flood of 1982, Rocky Mountain National Park

Lawn Lake is located at treeline, 3,350 m (10,987 feet) above sea level. It is in one of the most scenic areas of Rocky Mountain National Park, Colorado. In 1903, a privately constructed dam enlarged the lake to store water for irrigation. These activities preceded the designation of Rocky Mountain National Park in 1915; because of the established water rights, the dam continued to be privately managed, maintaining an easement within national park property.
On 15 July 1982, the dam at Lawn Lake failed, probably due to a piping failure. The subsequent flood sent approximately 831,000 m3 of water cascading down the Roaring River—causing the Cascade Lake Dam to fail—and then continuing through the town of Estes Park. Three people were killed, and nearly $30 million of damage occurred. The president declared Larimer County a disaster area on 22 July 1982.
Failure of the dam released a torrent that scoured the drainage of the Roaring River, inundated adjacent ecosystems, and deposited a large debris fan at the confluence of the Roaring and Fall rivers in the park. The physical and biological effects of the flood were profound, particularly within the park. As perturbations of this type in high-elevation ecosystems are rare, the flood captured the interest of local, national, and international scientists and scholars. Cont.